| .. SPDX-License-Identifier: GPL-2.0 |
| |
| ====================== |
| DCTCP (DataCenter TCP) |
| ====================== |
| |
| DCTCP is an enhancement to the TCP congestion control algorithm for data |
| center networks and leverages Explicit Congestion Notification (ECN) in |
| the data center network to provide multi-bit feedback to the end hosts. |
| |
| To enable it on end hosts:: |
| |
| sysctl -w net.ipv4.tcp_congestion_control=dctcp |
| sysctl -w net.ipv4.tcp_ecn_fallback=0 (optional) |
| |
| All switches in the data center network running DCTCP must support ECN |
| marking and be configured for marking when reaching defined switch buffer |
| thresholds. The default ECN marking threshold heuristic for DCTCP on |
| switches is 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps, |
| but might need further careful tweaking. |
| |
| For more details, see below documents: |
| |
| Paper: |
| |
| The algorithm is further described in detail in the following two |
| SIGCOMM/SIGMETRICS papers: |
| |
| i) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, |
| Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan: |
| |
| "Data Center TCP (DCTCP)", Data Center Networks session" |
| |
| Proc. ACM SIGCOMM, New Delhi, 2010. |
| |
| http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf |
| http://www.sigcomm.org/ccr/papers/2010/October/1851275.1851192 |
| |
| ii) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar: |
| |
| "Analysis of DCTCP: Stability, Convergence, and Fairness" |
| Proc. ACM SIGMETRICS, San Jose, 2011. |
| |
| http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf |
| |
| IETF informational draft: |
| |
| http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 |
| |
| DCTCP site: |
| |
| http://simula.stanford.edu/~alizade/Site/DCTCP.html |
